Artificial leg



l UNITED STATES PATENT FFICE.

O. D. WILCOX, OF EASTON, PENNSYLVANIA.

ARTIFICIAL LE Gr.

Specification of Letters Patent No. 16,420, dated January 13, 185'?.l

To all whom fit may concern:

Be it known that I, O. D. VILCOX, M. D., of Easton, in the county ofNorthampton, in the State of Pennsylvania, have invented a new anduseful Improvement on Artificial Limbs to be Applied in Cases ofAmputation at the Knee and Below It; and I do hereby declare that thefollowing is a full and exact description thereof, reference being hadto the accompanying drawings and to the letters of reference markedthereon.

The nature of this invention consists in the peculiar introduction ofelastic cords or muscles, with their conjoined tendons, extending fromthe sound part of the limb by which the motions of the leg and foot maybe effected and controlled.

To enable others skilled in the art to construct and apply thisinvention I will pro ceed to describe its construction and operation.

The limb is made of willow, covered with leather and coated withvarnish, which is shaded with the flake white, and Spanish Vermilion.

Figure l is a section of the leg. If the leg is not cut off close belowthe knee so that there is no stump to be fit-ted to, below the knee;then in the first place a socket of suiicient length should be made tofit it. Then the lower portion may be made and halved on around it, asshown at a, a; and at those places, as is also shown, oblique openv ingsmay be made for the passage of the fiexor and extensor tendons. At theankle it may be left as nearly solid as it can be to make the anklestrong; but openings in .the forward and back portions of it must bemade sufhcient for the tendons to work through, and for each end of thehalf circle of the foot to work in, as shown at b, Fig. 3. This portionof the oint is made by simply boring a hole through the ankle, whichmust be firmly bushed with brass.

F ig. 2, is the foot. This portion of the joint is made by a steelfiange upon each side, which run down and are firmly riveted to thefoot, as in this figure exhibited at 0.

The bottom portion of the heel is left solid as is shown in Fig. 3,sufficiently high to produce t-he stop motion, when the foot is bent toofar forward or back, instead of putting in those blocks as in myprevious patent limb, and then the half circle terminating at b b, ismade of brass with flanges turning out from each side of the bottom ofit,which are firmly fastened with screws to the foot.

D, is a spring to give elasticity to the foot when the leg is thrownforward as in walking.

E is a leather socket two thicknesses thick, made to fit the thigh, andlaced to it, the same as has been previously done; F, knee joints,portions of which run down onto the leg, under its covering, spreadingout as shown, and firmly riveted to the leg. A part of this joint alsoruns up between the two thicknesses of the thigh socket, and is fastenedto it with rivets. One such joint is put upon each side of the knee soas to act just with its center of motion. These joints are the same ashave been used for many years, and they may be halved together, or puttogether like a rule joint, with knuckles to produce the stop motionwhen properly extended. G is a leather strap nailed, screwed or rivetedto the leg, and laced to the bottom of the thigh socket, to assist inproducing the stop motion when t-he limb is properly extended.

H is a piece of gumelastic web which is stitched to the fore part of thethigh socket and runs down over the knee to the leg where it terminatesby being bound around the straight portions of a piece of wire shapedthus, U`, and a strong cord or tendon made of raw hide, is fastened toits loop. This tendon runs into the leg at the opening a and then downforward or the half circle at the ankle, and then through the bottom ofthe foot where it is fastened with a wedge. I is another elast-ic strapand tendon of the same kind which is stitched to t-he back of the thighsocket, and runs down back of the knee into the leg at a, and down backof the half circle through the bottom of the foot, where it is alsofastened like the first. The back one needs to be stronger than theforward one, though it need not be as long, because it does not have toextend so far. The openings in the leg for the passage of those tendonsmay be made just at the bot tom of the stump, and if there is no stumpbelow the knee to be fitted to, then the leg may be made in one piece,and the elastic straps may pass in at the top of the leg.

Operation: These elastic straps operate very much like the muscles ofthe natural limb; and they also terminate in tendons as the naturalmuscles do; consequently muscles and tendons will properly be the mostappropriate name for them. lVhen the knee is thrown forward, as inwalking, that extends the forward muscle over lthe knee, which throughits tendon raises the foot, so that it will clear foot mats, carpets,the dirt or whatever chances to be in the way, and at the same timethrows the leg and foot forward; but before it comes forward to itsplace, the back muscle is put upon the stretch, and as this is strongerthan the forward one it gradually checks and firmly stops its motion,and at t-he same time raises the heel bringing the foot down right tofit an ordinary surface; so that all is made most gracefully andnaturally to imitate nature in all of its motions.

If there is a sufiicient stump below the knee to adjust the artificialleg to it, then that will control the action of' the leg, though theartificial elastic muscles are then needed to control the action of thefoot. But in casesl where the leg is amputated close below the knee asit comparatively often is, then as may be at once realized, it is asnecessary to have something to control the motions of the leg and foot,as it is when the limb is amputated at the thigh.

l/Vhat I claim as my invention and desire to secure by Letters Patent,is-

The artificial elastic muscles with their conjoined tendons, runningfrom the thigh to thefoot as herein described to effect and to controlthe motions of the leg and foot, in cases of amputation at the knee andbelow it.

O. D. VILCOX.

Vitnesses:

IMMANUEL THUME, HENRY S. TROXELL.

